1 files changed, 8 insertions, 4 deletions
diff --git a/src/gleam/string.gleam b/src/gleam/string.gleam
index 851dbca..92d46b6 100644
--- a/src/gleam/string.gleam
+++ b/src/gleam/string.gleam
@@ -11,28 +11,32 @@ pub external fn uppercase(String) -> String = "string" "uppercase"
 pub external fn compare(String, String) -> order.Order =
   "gleam_stdlib" "compare_strings"
 
-pub fn reverse(string) {
+pub fn reverse(string: String) -> String {
   string
   |> iodata.new
   |> iodata.reverse
   |> iodata.to_string
 }
 
-pub fn split(string x, on pattern) {
+pub fn split(string x: String, on pattern: String) -> List(String) {
   x
   |> iodata.new
   |> iodata.split(_, on: pattern)
   |> list.map(_, with: iodata.to_string)
 }
 
-pub fn replace(in string, all pattern, with substitute) {
+pub fn replace(
+  in string: String,
+  all pattern: String,
+  with substitute: String,
+) -> String {
   string
   |> iodata.new
   |> iodata.replace(_, all: pattern, with: substitute)
   |> iodata.to_string
 }
 
-pub fn append(to first, suffix second) {
+pub fn append(to first: String, suffix second: String) -> String {
   first
   |> iodata.new
   |> iodata.append(_, second)